powerpc/mm/radix: Limit paca allocation in radix

[cascardo/linux.git] / arch / powerpc / mm / pgtable-radix.c

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 0472f8a..04ec976 100644 (file)
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -351,7 +351,25 @@ void radix__early_init_mmu_secondary(void)
 void radix__setup_initial_memory_limit(phys_addr_t first_memblock_base,
                                phys_addr_t first_memblock_size)
 {
-       /* Finally limit subsequent allocations */
+       /* We don't currently support the first MEMBLOCK not mapping 0
+        * physical on those processors
+        */
+       BUG_ON(first_memblock_base != 0);
+       /*
+        * We limit the allocation that depend on ppc64_rma_size
+        * to first_memblock_size. We also clamp it to 1GB to
+        * avoid some funky things such as RTAS bugs.
+        *
+        * On radix config we really don't have a limitation
+        * on real mode access. But keeping it as above works
+        * well enough.
+        */
+       ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
+       /*
+        * Finally limit subsequent allocations. We really don't want
+        * to limit the memblock allocations to rma_size. FIXME!! should
+        * we even limit at all ?
+        */
        memblock_set_current_limit(first_memblock_base + first_memblock_size);
 }